Week 10 in La Liga and something funny was going on. Athletic Bilbao kicked off against Granada with their goalkeeper nowhere to be seen – "I was still in the toilet when I heard the whistle," said Gorka Iraizoz – and Diego Simeone protested a red card … for his opponent. Mauricio Pellegrino became the eighth manager to get sent off so far this season and none of them is José Mourinho. Meanwhile, AS's front cover led on Real Madrid players celebrating and Marca too put them on the cover, which wouldn't be unusual but for the fact that the Madrid players in question were Madrid's B team players.

Piti scored twice for the first time in his career as Rayo Vallecano won away for the first time since February and Espanyol achieved the seemingly impossible and actually won away, 11 long months later. Málaga lost at home for the first time since March in the week when their owner finally decided to show his face. But not his wallet. Which, come to think of it, may not be quite such a coincidence after all. And not one manager got sacked, even though we're 10 whole weeks into the season.

The weekend's best goal was from Valladolid. Michael Essien, left-back, right-back, midfielder, and all-round smiling soldier, did the one thing that no one in Madrid ever expected Michael Essien to do: score a goal.

Cristiano Ronaldo, on the other hand, did not. Nor did Leo Messi. Nor, in fact, did Radamel Falcao. And that really is weird.

You have to go back to 10 December 2011 for the last time there was a round of La Liga games in which neither Messi nor Ronaldo scored. But while those two were going head to head at the Santiago Bernabéu, Messi providing an astonishing assist in Barcelona's 3-1 victory, the two cities' other teams were facing each other in Cornellà and Falcao was scoring.

It is over a year since a weekend's games went by in Spain without a goal being scored by any of them. On 26 October 2011, Barcelona beat Granada 1-0 with a goal from Xavi Hernández; Real Madrid defeated Villarreal, Karim Benzema, Kaká and Angel Di María scoring, and Atlético Madrid lost 3-0 at San Mamés.

This weekend, at last, the pattern was repeated. Real Madrid won 4-0 in one of those games where they are far too good without actually being very good; Barcelona ran risks but ran out winners and Messi, whose son Thiago was born the night before, played with a dummy down his sock but wasn't able to celebrate. As for Atlético Madrid, Falcao didn't score and they lost.

The difference this time was that Atlético losing was actually big news. Roberto Soldado hit a volley that was like David Platt's at Italia 90 only better and Nelson Valdez got a second in the fifth minute of added time to secure a 2-0 victory for Valencia at Mestalla. It was the first time Atlético had been beaten this season, ending their run of 13 consecutive victories and Falcao's run of scoring in every game he has played since 24 August.

Saturday night was the first time that Atlético had been beaten since April.

This was the game that announced a change at the top. Not the very top, obviously, but the other top. Spain's other league. Between them Valencia and Atlético are two of the only three teams other than Madrid and Barcelona (the other is Deportivo) to have won the league in almost 30 years and they have the third and fourth biggest stadiums in the country and the third and fourth biggest TV deals too.

When it comes to all-time points in the league, Valencia are Spain's third biggest club on 3,116 to Atlético's 3,057; when it comes to trophies won, Atlético are Spain's third biggest club on 25 to Valencia's 20. For three years in a row, Valencia finished third, the only side anywhere near Madrid and Barcelona and even they were nowhere near them.

Now, Atlético were set to take that position from them. From 14 points below Valencia at the start of 2012, they went into this game 14 points above.

And yet Atlético had not won at Mestalla in nine years and Valencia are one of only four teams against which Falcao has not scored since he came to Spain: he is on 49 goals. Meanwhile, they have not beaten Real Madrid since 1999. This has been their best start in history but, some said, they were yet to play one of the really strong teams: not Madrid, not Barcelona, not Valencia. And when they did they would come unstuck. This was the first proper test, some said. If so, Atlético did not pass it.

"It wasn't a pretty game," said Pellegrino. He was right, it was far from pretty, apart from Soldado's goal. It was, though, intense, aggressive, and fascinating. A proper battle that got nasty without ever really getting nasty, where there were clashes but few confrontations.

This was one of those battles where it felt like both sets of players enjoyed the fight, where there was a kind of shared admiration and a shared sense of purpose … right down to Pellegrino getting sent off in the first half for throwing a bottle down.

When the card came out, Valencia's manager became the latest victim of a crusade against coaches that prompted Miroslav Djukic, the Valladolid coach, to note "some people don't seem to realise that Franco's dead" and Rayo Vallecano's Paco Jémez to talk about living under a "dictatorship".

Rather than rub his hands in glee, Simeone stepped in to try to get the fourth official – likened to private security guards by Marca's Roberto Palomar because they need no qualification to walk round carrying a big stick – to change his mind.

Only Valencia's president, Manolo Llorente, broke that sense of shared struggle when moaned afterwards: "they should keep an eye on Falcao's elbows". And yet it was Falcao who got his head split open when Soldado trod on his head by accident — "I normally wear rubber studs but today I was wearing aluminium", the striker admitted — and who got dragged to the floor twice. He didn't get a penalty either time.

Atlético had just two shots on target and scored neither; Valencia had just two and both went in. The first, the wonderful volley from Soldado, the second a late neat goal from Valdez on the break, a barely discernible pause enough to draw Thibaut Courtois to finish.

With it, Atlético slipped three points behind Barcelona. Valencia meanwhile climbed to four points from a Champions League place.

Before Saturday night, Atlético had only been behind for 17 minutes all season. It was also only the second time that they have had more possession than their opponents — and only the second time that they have failed to win. That tells you something about the way they play; devastating on the break, hard to score against, competitive if not always creative. "I prefer to have one chance and score one goal than have 15 and score none," Simeone says. It might also have suggested that they will struggle against teams that sit deep and defend against them; this is not a side with the attacking variety of Madrid or Barcelona.

There might have been a temptation to see in this result something false about Atlético's run; to follow a well worn path and bemoan referees or bad luck, to slip into that familiar pessimism and hide yet again behind Atlético's status as Spanish football's Pupas, the jinxed one, for ever destined to lose out. But it didn't happen. This time it is different; Atlético are different. They will not win the league but they are the team best equipped to take third place — and get closer to Madrid and Barcelona than Valencia have over the last three years.

Especially after Simeone this week insisted that Falcao would not be leaving in the winter transfer window.

When Simeone was asked if Valencia was Atlético's first real test, he quite rightly replied: "You're forgetting Chelsea and Málaga" and they are still five points ahead of Real Madrid this morning. One defeat in 10 games is no disgrace; one defeat since April is an impressive run. Better than Madrid, for a start. And Barcelona. "We leave here with our heads held high," said Simeone. After the game there was no fatalism and no excuses. AS called it a mere "slip-up" while El Mundo Deportivo's Atlético supplement opened on one word: "Proud". And on a weird weekend that was the weirdest thing of all.